1. Field of the Invention
The present invention relates to a multi-cylinder internal combustion engine provided with a communicating passage that permits the respective internal spaces of plural crank chambers corresponding to plural cylinders communicate.
2. Description of Background Art
A multi-cylinder internal combustion engine is known wherein a communicating passage for permitting adjacent crank chambers to communicate outside a crankcase is provided to a skirt under a cylinder block. See, for example, JP-A No. 2006-70795 (FIGS. 1, 3). In such technique, the skirt is required to be extended to secure space for arranging the communicating passage in the skirt, however, when the skirt is extended, the height of an engine is increased, and the engine may be large-sized.
In the related art in which a communicating passage is permitted to flow inside a cover overhanged outside a crankcase between adjacent cylinders is provided to a skirt on the downside of a cylinder block. See, for example, JP-A No. 2006-70795 (FIGS. 1, 3). In such art, as the communicating passage protrudes outside the case, a mounting layout may be restricted. More particularly in a motorcycle, restrictions interference with the arrangement of the exhaust pipes on the front of the cylinder should be prevented. A degree of freedom in relation to the arrangement is lower with respect to a motorcycle as compared to an automobile.